1. Field of the Invention
The present invention pertains to the art of cooking appliances and, more particularly, to a control system for a cooking appliance which enables the appliance to perform a cooking operation without an initial preheat period.
2. Discussion of the Prior Art
Conventional cooking appliances generally perform cooking operations through radiant heat developed from bake and/or broil heating elements. Such types of cooking appliances can take various forms, mainly ranges and wall ovens. When utilizing a conventional cooking appliance, the oven is initially controlled to proceed through a preheat cycle in order to establish a desired cooking temperature. Oftentimes, a signal is provided to a user when the preheat cycle is complete in order to indicate when the food to be cooked should be placed in the oven. In some cases, both the bake and the broil elements are actuated during the preheat cycle. The oven preheat is typically required for short cook time items, such as packaged food items e.g. frozen pizza and TV dinners, as well as baked goods such as cookies, biscuits and the like.
Since their introduction, packaged food products have grown in popularity with modem consumers. Most, if not all, packaged food items have imprinted upon their labels preparation instructions that include time and temperature parameters. Typically, the preparation instructions also include an oven preheat requirement. That is, prior to placing the packaged food item into a cooking chamber of an oven, that oven must be preheated according to the preparation instructions. Generally, the preheat takes in the order of 10-15 minutes to bring the cooking chamber to or near a desired temperature. Therefore, in order to determine an overall preparation time, a consumer must add the preheat time to the actual cook time. Likewise, recipes for baked goods and other short cook time items establish cook time parameters based upon the oven being preheated.
Since cooking times set forth in recipes or other cooking instructions are established based on an oven being preheated, failure to preheat the oven directly affects the overall food preparation. Under such circumstances, the user must either mentally determine a supplemental cooking time period for the food item or, if the cook time is not altered, the food will be at least slightly undercooked. Thus, the consumer must take into account the preheat time of the oven when preparing a meal. However, due to haste, busy schedules or other time constraints, this additional time is not always allotted and, therefore, the consumer is faced with either consuming a partially undercooked meal or continually checking to see when the food item has cooked completely. In any case, unless the oven is preheated, the food item is not cooked in a satisfactory manner within the established time parameter.
Based on the above, there exists a need in the art for a system that will enable a consumer to readily perform a cooking operation within established time parameters without requiring that the oven be initially preheated. In other words, under conditions wherein a cooking operation is to be performed, it would be beneficial to enable the consumer to easily perform a cooking operation that automatically compensates for the lack of a preheat cycle while, at the same time, not extending the established time parameter.
The present invention is directed to a control system for a cooking appliance which enables a consumer to selectively perform a complete cooking operation in a standard mode or in a no preheat mode. More specifically, in the no preheat mode, the control system modifies operation of the oven so that the cooking operation is completed, despite placing a food item in a cold oven, within established time parameters, i.e., within a time period specified in on package label or as set forth in a recipe. The present invention is particularly adapted for use in connection with short cook time items, such as frozen pizzas, cookies, biscuits and the like, rather then long term items, such as roasts.
In accordance with the most preferred embodiment of the present invention, when the no preheat mode is selected, the cooking operation is performed using a two-stage process. Initially, the control system operates one or more heat sources at a maximum heat output for a first predetermined period. At the termination of a first period, the control system operates the heat source(s) at varying heat output levels for a second predetermined period. Preferably, the second period includes a plurality of stages, between which the operation and heat output of the heat source(s) is adjusted so as to match a level of heat capable of being absorbed by the food item. In this manner, the control system can complete the cooking operation within established time parameters without requiring the oven to be initially preheated.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.